Tramlines are open tracks that are purposefully left unseeded in a field by a planter so that vehicles performing subsequent operations (such as chemical application) can use the tramlines as a path through the field, thereby avoiding damage to existing plants. Since vehicles used for seeding a field (such as a planter, seeder, or drill) and for these subsequent operations (such as a sprayer) are usually significantly different widths (for example, the width of a sprayer may be multiple times the width of a seeder for the same field), calculations must be performed before or during the planting operation to determine when seeding units on the planter should be turned off or disabled, so that seed is not put down in the locations where the tramlines will be.
Please note that the terms “planter” and “seeder” may be used interchangeably throughout the specification. In practice, a planter and a seeder are sometimes seen as distinctly separate vehicles or implements, albeit with a similar purpose, with the planter used for row crops with larger spacing between rows (such as corn) and the seeder being used for crops with a smaller spacing between rows (such as wheat). However, it is difficult to find a standard definition for these pieces of equipment. For the purposes of discussion within this specification, the terms “planter”, “seeder”, and “drill” (another term used in industry, typically synonymous with “seeder”) shall be assumed to be interchangeable, and each shall refer to an agricultural machine (either a self-propelled vehicle or a tow-behind implement) the purpose of which is to place crop seeds, bulbs, roots, and/or plants into the ground as an agricultural crop. The preferred term used in this specification shall be “planter” and this term will be used for the majority of the references. The term “agricultural planting machine” will be used when a single, generic term is needed for these type of vehicles, such as in the claims for this invention.
It should also be noted that the inventive concept described herein refers to two separate types of agricultural machines that work together to first plant a field and later maintain the field. For the purposes of this discussion, it is assumed that a first agricultural machine (the “planter,” as defined in the previous paragraph) will perform an operation which plants a crop in at least a portion of a field, and a second agricultural machine, or “subsequent vehicle,” will pass over the same field or portion of a field at a later time, after the crop has been planted. The “subsequent vehicle” may be a chemical sprayer, a fertilizer spreader, an implement pulled by a tractor, or any other appropriate type of vehicle which may need to pass over a previously planted portion of a field. Since a sprayer is a common type of “subsequent vehicle,” a sprayer is often used as an example within this specification. However, the use of a sprayer in the figures or corresponding discussion is as example only, and any other appropriate type of “subsequent vehicle” may be used without deviating from the invention concept presented herein.
To create the tramlines using systems available in the prior art, a planter typically needs to know the boom width, wheelbase, and tire width of the subsequent vehicle (such as the sprayer). This is because there are a line of seeding units mounted in a line on the back of the planter, each seeding unit corresponding to a planted row in the field. If the operator of the planter can control (enable and disable) the individual seeding units on the back of the planter, then individual rows can be disabled in the locations where it is desired to have a tramline. If the planter and the sprayer were identical widths, then the tramline solution could be designed into the planter itself (by simply not having seeding units in the locations where tramlines will be, so that these rows are never planted. However, it is not practical to have an implement with a large number of individual seeding units (whereas extending a long spray boom, which does not engage the ground, is relatively easy and desirable). Therefore, the width of the sprayer is typically some multiple of the width of the planter. The number and side-to-side location of seeding units that need to be turned off for a given pass of the planter will vary from one pass through the field to the next.
Planting systems in the prior art are capable of automatically calculating which seeding units should be turned off for a given pass. U.S. Pat. No. 7,591,226 by Dix et al. of CNH America (hereafter the “'226 patent”) describes a planting system which determines which seeding units to disable based on the width of the sprayer or “subsequent vehicle” (and its wheel base, tire width, etc.) as well as the corresponding width and configuration information for the planter. For instance, if we assume the sprayer is approximately five times the width of the planter, the rough location of the desired tramline (that will work for the sprayer) can be calculated by the ratio and relationship of the widths of the two vehicles. That is, it is possible to calculate which rows (which seeding units) should be disabled on the planter as it passes through the field by calculating the desired tramline location for the sprayer (or other subsequent vehicle) based on the sprayer's width and configuration. As long as the width of the sprayer is an even multiple of the width of the planter, and the configuration of each machine is known to the planter, this approach works relatively well.
However, this approach has its limitations. The approach described in the '226 patent requires that the configuration of the subsequent vehicle be known to the planter, so that the calculations of which units to turn off can be made as the planter makes passes through the field. If the same planter is used in conjunction with two different kinds of sprayers (with different configurations and widths), such as might be the case with a contract spraying operation open to different farmers, then the planter has to know which field it is on or which sprayer is used in that field.
What is needed in the art is a system and method for generating agricultural tramlines which does not rely on knowing the physical size and configuration of a subsequent vehicle.